JP2002213994A - Backup power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backup power supply device excellent in reliability and maintainability without losing of backup data of an absolute encoder. SOLUTION: The backup power supply device 6 comprising a primary battery 7 connected in parallel to a backup capacitor 4 and a detachable connecting terminal 8 is connected to one of second connecting terminals 9 connected in parallel to a main power source 5 of a motor controlling device 3. The other of the second connecting terminals 10 remains unconnected for use in exchanging to a new backup power supply device 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data backup of an absolute encoder used as a rotational position sensor of a servo system.

[0002]

2. Description of the Related Art AC servomotors are used in industrial equipment such as robots in terms of high positioning accuracy, reliability, and maintainability. An optical absolute encoder is used in the AC servomotor to perform high-precision positioning.

[0003] A servo system using a conventional absolute encoder will be described with reference to the drawings. As shown in FIG. 2, power is supplied from a motor control device 23 to power supply lines 24 and 25 to an absolute encoder 22 connected to a servomotor 21, but the main power supply to the absolute encoder 22 is cut off. A backup power supply unit is provided for backing up the position data even when the operation is performed, and the stop position data of the AC servomotor is backed up.

[0004] As backup means for position data,
Known are those in which a charging circuit and a rechargeable secondary battery are connected in parallel with the power supply line of the main power supply, and those in which a primary battery and a backup capacitor are connected in parallel with the power supply line of the main power supply.

[0005] Hereinafter, as a general backup means,
An absolute encoder using a primary battery and a backup capacitor will be described.

In FIG. 3, reference numeral 31 denotes a servo motor;
Is an absolute encoder, 33 is a motor controller,
A main power supply unit 34 supplies power to the absolute encoder 32 during normal use. Reference numeral 35 denotes a backup capacitor that stores electric energy when power is supplied from the main power supply unit 34 and uses the previously stored electric energy when power from the main power supply unit 34 is shut off for a relatively short time. Back up your data. Reference numeral 36 denotes a connection terminal for connecting a primary battery.
Connect and use. When the power from the main power supply 34 is cut off, the primary battery 37 backs up data for a relatively long time. Then, it is necessary to replace the primary battery 37 before detecting a drop in the output voltage of the primary battery 37 and making it impossible to back up the data of the absolute encoder.

Next, a method of replacing the primary battery 37 will be described. There are two methods. One is the main power supply unit 3.
In this method, the primary battery 37 having a reduced output voltage is removed from the connection terminal 36 while the main power is supplied from the power supply 4, and a primary battery having a sufficiently high output voltage is connected.

Another is a backup capacitor 3.
In this method, the primary battery 37 with a sufficiently low output voltage is connected to the primary battery 37 with a sufficiently high output voltage after the primary battery 37 with a reduced output voltage is removed from the connection terminal 36 without supplying the main power supply.

[0009]

In the above conventional method for replacing a primary battery, when the primary battery is replaced without supplying the main power, the primary battery having a lowered voltage is removed from the connection terminal, and the primary battery having a sufficiently high output voltage is removed. Until is connected, only the backup capacitor supplies backup power.

However, since the backup capacitor can supply the backup power for a short time due to aging, or its rate of change deteriorates depending on the use conditions, the backup capacitor can be supplied for a long time after the production. However, there is a problem that the backup capacitor cannot be easily replaced.

On the other hand, when the main power supply is kept supplied, the main power supply unit is often linked to a high-voltage power supply for driving the motor, and there is a possibility of a short circuit or the like, so that the primary battery cannot be replaced. There were also problems.

In addition, when the charging method is used, there is a problem that peripheral circuits become large and expensive.

An object of the present invention is to solve the above-mentioned problem of the prior art, and to provide a backup power supply device excellent in reliability and maintainability without losing backup data of an absolute encoder in a servo system at a low cost. With the goal.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a servomotor equipped with an absolute encoder, a motor control device for controlling the servomotor, and a main power supply unit of the absolute encoder being shut off. A backup capacitor for backing up data when the backup capacitor is connected, and the backup capacitor is connected to the main power supply unit of the absolute encoder using a detachable connection terminal, so that the backup capacitor can be easily replaced. .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve this problem, the present invention provides a servo motor equipped with an absolute encoder, a motor control device for controlling the servo motor, and a data controller when a main power supply of the absolute encoder is shut off. And a backup capacitor for backing up the backup capacitor, and the backup capacitor is connected to the main power supply of the absolute encoder using a detachable connection terminal, so that only the backup capacitor can be replaced.

Also, in the case where at least two second connection terminals for connecting the backup power supply device are provided in parallel, and the connection terminal of the backup power supply device is connected to at least one second connection terminal, At the time of replacement, a new backup capacitor can be connected to the second connection terminal that is not connected, so that backup data is not lost.

In the case where at least one second connection terminal is provided other than the servomotor, the installation location is flexible and the work of replacing the backup power supply device is facilitated.

Further, when the primary battery is connected in parallel with the backup capacitor, the backup capacitor and the primary battery can be easily replaced at the same time, and reliability and maintainability can be secured.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a servo motor, 2 is an absolute encoder, 3 is a motor control device for controlling the servo motor 1, 4 is a backup capacitor,
The position information data is backed up when the main power supply unit 5 of the absolute encoder 2 is shut off. Reference numeral 6 denotes a backup power supply device. In this embodiment, a primary battery 7 is connected in parallel to the backup capacitor 4 and has a detachable connection terminal 8.

The main power supply unit 5 of the motor control device 3 is provided with two second connection terminals in parallel with the connection terminals 8 of the backup power supply device 6, and one of the second connection terminals 9.
Is connected to the connection terminal 8 of the backup power supply device 6, and the other second connection terminal 10 is not connected.

The backup capacitor 4 as in the prior art
Is charged while the absolute encoder 2 supplies power from the main power supply unit 5. When the power supply from the main power supply unit 5 is cut off, the position information data is backed up by the backup power supply device 6 (the backup capacitor 4 and the primary battery 7).

Further, when the supply voltage of the backup power supply device 6 falls below a specified value, the backup power supply device 6 needs to be replaced, and the old backup power supply device 6 is connected to the second connection terminal 9 to prevent data loss. The new backup power supply 6 is connected to the second connection terminal 10 while the connection is still established, and then the old backup power supply 6 is removed from the second connection terminal 9 so that the backup power can be easily erased without erasing the absolute data. The supply device can be replaced.

The second connection terminal 9 and the second connection terminal 10
Need not be installed in the motor control device as in the present embodiment, and the installation location is, for example, equipped with an absolute encoder other than the servomotor 1 for the convenience of replacement. May be installed in a device in which the servo motor is installed, a controller that controls a motor control device, or the like.

In the present embodiment, the second connection terminal is
However, even if three or more second connection terminals are provided in parallel, the connection terminals need only be electrically equivalent to each other, and the same effect can be obtained.

Further, if the backup power supply device is constituted by the backup capacitor and the connection terminal, it is easy to replace only the backup capacitor.

[0027]

As is apparent from the above embodiments, according to the first and second aspects of the present invention, replacement of the backup capacitor is facilitated. Further, since two or more second connection terminals are provided, the backup power supply device can be replaced without losing the backup data of the absolute encoder.

According to the third aspect of the present invention, in the case where at least one second connection terminal is provided other than the servomotor, the installation location is flexible and the work of replacing the backup power supply device becomes easy. The degree of freedom in equipment system design can be expanded.

As described above, a backup power supply device excellent in reliability and maintainability can be obtained at low cost without losing the backup data of the absolute encoder.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a backup power supply device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of data backup in a conventional servo system.

FIG. 3 is an explanatory diagram of a conventional backup power supply device.

[Description of Signs] 1 Servo motor 2 Absolute encoder 3 Motor control device 4 Backup capacitor 5 Main power supply unit 6 Backup power supply device 7 Primary battery 8 Connection terminal 9, 10 Second connection terminal

Claims (4)

[Claims] A servo motor equipped with an absolute encoder, a motor control device for controlling the servo motor, and a backup capacitor for backing up data when a main power supply unit of the absolute encoder is shut off; A backup power supply device in which the backup capacitor is connected to a main power supply unit of an absolute encoder using a detachable connection terminal. 2. A method according to claim 1, wherein at least two second connection terminals for connecting the backup power supply device are provided in parallel.
The backup power supply according to claim 1, wherein a backup power supply is connected to the two second connection terminals. 3. The backup power supply according to claim 2, wherein at least one second connection terminal is provided other than the servomotor. 4. The backup power supply device according to claim 1, wherein a primary battery is connected in parallel to the backup capacitor.